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Event is shaping well, buit will be slightly less well attended than Falmouth.

The Royal Canadians: Fill Your Hands, sailed by Billy and Norm, New foil package.

Groupama: Franc and Louis, refined championship boat.

Hydros 1 &2 both entered but I don't know who is sailing them. Both have new pieces but I don't know specifics.

Sentient Blue, Now German, using Heemskerk foils on 2007 platform and wing. Don't know who is sailing, could be Paul and Helena.

Les Quebecois: Boat racing to the race.

AXON Racing: Sailing Cogito. Boat as sailed in 2013, but actual french will be spoken aboard instead of MacLane's Inspector Clouseau ( CHEIF Inspector Clouseau) style french. Benoit Marie and Benoit Morrelle are training with Clark in the US in July and providing local knowledge in September.

Aethon USA 105, re-grooved for the event with new foils, canting wing and a few other small tricks. As always, we are trying to out think everyone. Steve Clark and Mike Costello. Wing testing going OK, new foils showing up any day, hulls would float now, lotts of other boxes to check. Our stack of Manana cards is waffer thin.

Not showing up:

Invictus Conserving assets and energy for a new build, which weill be delayed until the last possible moment and then will only make it as the result of heroic effort.

Flying Frogs Won't be shipping PLVI to the alps, and hasn't got the mojo to do anything better.

City Of Cascais Portugese boat that made a ceremonial appearance and beam failure at Falmouth..... Sorry but who builds a hollow, curved dolphin striker strap? Who thinks it is a good idea?

Itallia Team from Scily has gone dark, no word ion a while, I think there are some pretty decent hulls there and mnaybe tooling for good wings, but nothing on the water. Lots of promise but no delivery.

I don't know anything more: It seems that someone would put a big rig on a Phantom and try to humiliate us, but I don't think there arte any other actuall C Class catramarans out there that could or would show up.

SHC

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Thanks Steve for the birds-eye-view update! Sounds like everyone is busy finishing bits and pieces. And yes we (i.e. "les Quebecois") are racing to the race! It looks like we will be the last ones on the water. Having said that, my joker is that we are the only team to have built a entirely new boat, from scratch:-)

Anyway I can give a fresh update from Montreal.

Our hulls are in the last stage of fabrication, i.e. just adding the daggerboard cases. Plateform assembly should be well advanced by the end of the week, depending on a few missing bits and pieces...

A prototype set of our hydrofoils has been tested by the Mystere Composites team on their Espadon Air Design 20ft catamaran. Results have been very encouraging with some good speed and stability. Our set of foils and rudders are being built as we speak by the Mystere team.

The wing is also at an advanced stage of completion. The front element is 90% complete. The flap / rear element is 60% or 70% complete. Most of the wing assembly should be complete by next weekend.

We are on track to be hitting the water on the weekend of July 4th and 5th. We should have 1 months testing and debugging before we ship the full kit to Switzerland.

There are still some questions marks on some key elements, especially shipping and budget. We are keeping our head down and hoping for the best.

I have to give a big shout to all the people who have supported us and helped us get this far, especially all our sponsors who have trusted us to deliver! We hope to make a good showing in Geneva and make them proud.

Overall I have been really impressed by the resourcefulness of the team and what we have manage to achieve considering where we started from. Few would have given us much chances of making it this far. For sure we have had to make many compromises along the way to save time and/or money. The result will be a boat that is slightly heavier than we would have liked but it's not a bad effort for a first attempt. It will be a tremendous plateform to work from in the future.

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So, um, silly question - how fast is a C Class? Compared to an F18 or T? Is a wing an essential item, or just a bit of geeky fun? I guess I'm wondering whether an Olympic level crew could compete in a budget boat against a state of the art design sailed by a good-but-not-Olmpic-standard crew?

For me, the wing is the vital ingredient. Consider that some of the sailors are already Olympic standard and that others have been doing it long enough to be seriously good, most would say that without a wing, you would be so far behind it's not worth showing up, however good you are.

A few years ago, Glen Ashby (best cat sailor of his generation?) sailed a boat with Jimmy Spithill crewing and yes,at times he was great but when it came to the final match, the non Olympic crew of Fred and Magnus had too much speed for them and could sail their boat sufficiently well enough to win comfortably.

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It all depends on how fast everyone really is rather than how fast they say they are.

We definitely crush T Cats, so by extension F-18s and anything else that doesn't foil.

Reports from the foiling cats are so glowing that I'm skeptical.

I cannot recall being passed by anything that wasn't another C Cat.... or 55 feet long.

SHC

My loose calcs from last LAC showed that Moth is faster around a course in anything over 7 knots, same with GC32 or other foiling cats in that size range. C gets smoked downhill.

Don't have sufficient data on Nacra FCS20 or Phantom, it's probably more of a foil design/sailor skill and RM question for the cats in similar size range.

Not sure anything in the world is as quick as 2010 C-Class winner Canaan in under 6 knots, but certainly the C is still 'the fastest course racing boat in the world' in only a very narrow range of conditions. Very excited to see if development since '13 means the C has regained some of her crown.

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Its probably a comparison about as reliable as an angler's estimate of fish size, but in the UK Portsmouth Yardstick system the International Moth has just achieved a faster rating than the 1973 C Class catamaran one, which was the lowest ever previously. That was in the days of conventional rigs, not even wing masts. Back then the Cs were sensationally faster than everything else on the water. I'm not sure things are so very different now.

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Could be easily tested, there's a moth fleet just a few miles away with some pretty good sailors. I don't know what the #'s are, but my guess is that the moth would need more than 7 kts to not look too ridiculous. When are you shipping your boats Steve?

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I think it would only be in a very narrow wind and wave range where a moth could potentially be faster than a C. Some of the days at last year's C regatta might have suited the moth but certainly not the light ones. On the other hand most of the big/rough days at this years Sorrento moth regatta would have destroyed all of the CCats.

If its under 12 kts wind the moth will sail upwind and down wind at wide angles and I think the C with its rig up in better winds would have the advantage. Above 20kts wind the C becomes a handful but the moth can keep going up to 30 if the water is flat enough. But even in 15kts if the water is too rough the C will keep going while the moths will be crashing or slowing down for safety. I suspect the Cs might have an effective wave size limit too but surely its bigger than the moth safety limit.

In moderate winds and smooth waters the moths are only moderately faster than the ACats upwind. The C's would have to be quicker. Downwond the Moths are way quicker than even the foiling As and while the Cs are quicker than the As obviously, I am not sure they are as quick as the good moths.

Top guys rarely get to 30 kts boat speed while racing, mid fleeters like me rarely get over 25, All the big numbers are in extreme conditions without aiming for VMG to a mark. The guy who claimed 36 placed behnd me at Sorrento so I doubt he got over 25, which makes his 36 a bit suspect. Neither the As nor Cs are not going any faster. All the big numbers from CG32 and beach cat foilers in races are in the same range.

The GC 32 has gone faster at times, so in some conditions it may well be the fastest of this bunch, especially now they have been raced hard by good people for a while and they must be learning how to get more out of them.

Thats long been the problem with C Cats, its always been a design race with boats finished too late to sort out and optimise on the water. I am not sure that has changed at all based on Steve's list of potential entries this year.

Great boats to follow though, always brilliant ideas, been that way since the 60s. More please.

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In moderate winds and smooth waters the moths are only moderately faster than the ACats upwind. The C's would have to be quicker. Downwond the Moths are way quicker than even the foiling As and while the Cs are quicker than the As obviously, I am not sure they are as quick as the good moths.

Not sure if this is relevant to the discussions, but at the recent Wangi regatta, we had a chance to see where the best A's were against the Moths - we saw Josh McKnight against Stevie Brewin in 10 knots and flat water. Upwind, the Moths kill the A's. The A's go a little higher but the Moth is probably 3 knots quicker. Downhill, there was almost no difference in speed and angle, but as soon as there was a gybe, the Moth stayed foiling and pulled significant distance. Just to be clear - this was what Stevie told me because I was too far away to see!

I would expect the C to make up a fair bit of the upwind difference. The interesting question would be what happens downhill. Unless the C can gybe downhill, they would have to be so much quicker downhill than the Moth to make up for the losses.

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you're not still on that video, are you? We should have put something up at the beginning that says: "For entertainment only."

Again, having watched, recorded, analyzed, etc. every C fleet for the past 3 events, and most of the foiling Moth Worlds, the comparison is fairly simple:

non-foiling Cs maxed out in the low 20s, even the best ones. The top moths sail 27-30 knots downwind in anything over 15, and make massive gains to leeward as they carve through a foiling gybe. My guess is that Franck might get to that speed number, but we never saw him hit 30. Hydros occasionally got into the 30s just before a huge wipeout. No one foiled through gybes.

Top moths sail 16-19 knots upwind at around 50 degrees. C's are a bit slower and higher from my experience. Franck was same/higher when he got the upwind foiling hooked up.

If the full fleet is foiling, it might be close, but in order to have the lift to be able to sail the boat well (Groupama C), it seemed in Falmouth that you could not have high-speed foils.

Very excited to have this proven wrong sur le lac!

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^solid data analysis. However, I remember trying to chase Cogito down in Newport around 2007 in an early foiler moth and getting badly stomped. Now, the moth advanced a bunch since then, but so has the C. On a visceral level, I have a hard time believing that the foiling C loses to the moth. Just my experience.DRC

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Steve, I wish you the best for this event. This should be interesting. Hopefully you will post some pictures of the retooled Aethon once it is too late for any team to make changes that mirror the ones that you have done. Glad to see that the Canadians re going as well. Get some great training and have a safe trip. Thanks, TTS

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^solid data analysis. However, I remember trying to chase Cogito down in Newport around 2007 in an early foiler moth and getting badly stomped. Now, the moth advanced a bunch since then, but so has the C. On a visceral level, I have a hard time believing that the foiling C loses to the moth. Just my experience.

DRC

No offense DC but the difference between what you could do on an early foiler and what a top guy can do on the latest moth is probably around double.

And the performance gains realized by the C-Class without two-boat testing or one-design platforms are going to be significantly less than what any of the Moth teams have learned.

Unless there is a real, game-changing design advance for 2015, which is why we all pay attention to the C-Class anyway, isn't it?

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you're not still on that video, are you? We should have put something up at the beginning that says: "For entertainment only."

The top moths sail 27-30 knots downwind in anything over 15, and make massive gains to leeward as they carve through a foiling gybe. My guess is that Franck might get to that speed number, but we never saw him hit 30. Hydros occasionally got into the 30s just before a huge wipeout. No one foiled through gybes.

Top moths sail 16-19 knots upwind at around 50 degrees. C's are a bit slower and higher from my experience. Franck was same/higher when he got the upwind foiling hooked up.

Moth figures are a little optimistic. When VMG running in big breeze, top moths stay on average around 25 knots, going 27-28 in the big gusts. the 30s are seen only in the bearaways, at the bottom marks, or when reaching out of the course.

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^solid data analysis. However, I remember trying to chase Cogito down in Newport around 2007 in an early foiler moth and getting badly stomped. Now, the moth advanced a bunch since then, but so has the C. On a visceral level, I have a hard time believing that the foiling C loses to the moth. Just my experience.

DRC

No offense DC but the difference between what you could do on an early foiler and what a top guy can do on the latest moth is probably around double.

Oh yeah, I fully agree. Plus I only weighed about 130lbs and have learned a lot as a sailor since. It's just really hard on a gut level to imagine such a powerful sailing machine getting so comprehensively stomped. It's wonderful for the sport that a solo foiler is so dominantly fast. The C-class needs a minimum shore/RIB crew of 1 to even go for a practice sail whereas the moth needs zero. In that regard, foilers have liberated speed sailing in a way never before realized. Living in the future is awesome.

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I've only real done analysis with top ten range boats at a world championship. - 2 all around for mid-fleet seems about right.

If an M32 beats a moth, would not a top of the line C?

hahahaha

you're not still on that video, are you? We should have put something up at the beginning that says: "For entertainment only."

The top moths sail 27-30 knots downwind in anything over 15, and make massive gains to leeward as they carve through a foiling gybe. My guess is that Franck might get to that speed number, but we never saw him hit 30. Hydros occasionally got into the 30s just before a huge wipeout. No one foiled through gybes.

Top moths sail 16-19 knots upwind at around 50 degrees. C's are a bit slower and higher from my experience. Franck was same/higher when he got the upwind foiling hooked up.

Moth figures are a little optimistic. When VMG running in big breeze, top moths stay on average around 25 knots, going 27-28 in the big gusts. the 30s are seen only in the bearaways, at the bottom marks, or when reaching out of the course.

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Yes, Mid fleet moths are in the order of 2kts slower than the champs, but more is lost in tacks and gybes than straight lining. In some of our club races we do 5 laps and I have a good day if Dave Lister does not lap me. So anyone judging moth speed based on a mid fleeter like me can consider the very best boats are 20-25% faster around a course.

3) 3di trampoline sealed to centerline of hulls, and with end plating of wing provides significant up force out of trampoline, improved driving force from wing and lower induced drag. Numbers from study are stupidly big. I really find it hard to believe what the machines are telling us, but if it is even half true....

4) Main beam fairing far more aggressive than last time, to try to get some positive camber into the trampoline and get a good seal with minimum sail area.

Weight hasn't improved, but that's what happens when you substitute 18 kg hydrofoils for 5 kg centerboards. I am 10 kg lighter however and mike weighs about 15 kg less than Oliver

We have a metric shitload to figure out, and not a lot of time before they start scoring, so I expect we are well behind. Hopefully we can catch up and make it somewhat interesting. So far the testing has been a complete gas or as frustrating as anything I have ever done on the water. Sometimes the difference is really small.

Looks really good Steve-best of luck! Does altitude control work like an uptip foil , a surface piercing foil or manually? Does the whole foil contribute, to some degree, toward lateral resistance? I noticed the wingtip foils-pretty cool.

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Steve talks about pulling the windward board full up. Post 37# shows two guys generating enough RM to require plenty of lateral force & it looks to be all or almost all coming from the foil that is down.

Steve,

SNAKEfOIL. Really. Snakefoil makes all kinds of sense, but then you had to go one step further. I am certain you realize the comments your "almost all caps" choice is just begging for. Have fun with that.

On the tech side, I really hope it pans out.

On the other hand, consider this: Given the moment arm, you may be at the top of the heap for foil bending loads vs boat weight. What if it works too good? Just think of how much could be spent on carbon trying to copy this concept over to other boats. And that leads to thinking about that sickening/horrible sound of snapping carbon just waiting for any "not quite enough carbon" attempts.

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SCARECROW; The problem isn't so much the carbon, although there is an impressive ammount, it is the purchace to retract them once they are all the way down. We kind of spaced on what way the bord was going go as they loaded up. Turns out that the head wants to disappear down into the hull as the blade essentially rotates around the bottom bearing. boat has to be almost completely stopped before the crew can haul it up by the head. The section at the highly curved area is quite fat and symetrical for structural reasons and also to make the boat more docile when that part of the blade hooks up in a wave or something.

We built some crane/ horn structures which the Fench call 'goats' to which we have added an increasingly awsome amount of mechanical advantage. Problem is that these hulls only weigh anbout 75 lbs, so there aren't many places stong enough to attach a 48:1 cascade. The loads are almost as big as the shrouds and we really would like to be able to adjust the cant angle on the fly.

As it is we use a 1/2 titanium pin top set the cant angle.

Doug; the design is heave stable by the same mechanism of most surface piercing foils. The foil surface becomes less efficient as it getys closer to the surface, and therefore delivers less lift. There is a reflex curve in the span, which means that the foil loses horizontal projected area faster than it loses vertical projected area. We can adjust the ratio by deciding how far to let the blade rotate as it extends. There is an worm gear which adjusts the angle of attack of the foil, much like on every other catamaran. Unlike the Melvin foils, we do not use leeway to control heave. We also don't have the tip breaching the surface.

We have had some trouble with the boards over producing side force when sailing down wind, so sometimes we saildown wind with the weather board down about 2 feet. This isn't optimal, but we have had some very nice rides at very deep angles. Upwind, over producing side force isn't the bummer it used to be when the hull was in the water. In fact there is absolutely nothing wrong with crabbing to windward as long as you are foiling.

The ride is really amusing, it's kind of bouncy, I guess because the foils bend and there is a bunch of visco-elasticity in the water. This is unintended, but could be cool in a sort of trampofoil flapping foil way. All in all, way too much fun for someone my age.

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SCARECROW; The problem isn't so much the carbon, although there is an impressive ammount, it is the purchace to retract them once they are all the way down. We kind of spaced on what way the bord was going go as they loaded up. Turns out that the head wants to disappear down into the hull as the blade essentially rotates around the bottom bearing. boat has to be almost completely stopped before the crew can haul it up by the head. The section at the highly curved area is quite fat and symetrical for structural reasons and also to make the boat more docile when that part of the blade hooks up in a wave or something.

We built some crane/ horn structures which the Fench call 'goats' to which we have added an increasingly awsome amount of mechanical advantage. Problem is that these hulls only weigh anbout 75 lbs, so there aren't many places stong enough to attach a 48:1 cascade. The loads are almost as big as the shrouds and we really would like to be able to adjust the cant angle on the fly.

As it is we use a 1/2 titanium pin top set the cant angle.

Doug; the design is heave stable by the same mechanism of most surface piercing foils. The foil surface becomes less efficient as it getys closer to the surface, and therefore delivers less lift. There is a reflex curve in the span, which means that the foil loses horizontal projected area faster than it loses vertical projected area. We can adjust the ratio by deciding how far to let the blade rotate as it extends. There is an worm gear which adjusts the angle of attack of the foil, much like on every other catamaran. Unlike the Melvin foils, we do not use leeway to control heave. We also don't have the tip breaching the surface.

We have had some trouble with the boards over producing side force when sailing down wind, so sometimes we saildown wind with the weather board down about 2 feet. This isn't optimal, but we have had some very nice rides at very deep angles. Upwind, over producing side force isn't the bummer it used to be when the hull was in the water. In fact there is absolutely nothing wrong with crabbing to windward as long as you are foiling.

The ride is really amusing, it's kind of bouncy, I guess because the foils bend and there is a bunch of visco-elasticity in the water. This is unintended, but could be cool in a sort of trampofoil flapping foil way. All in all, way too much fun for someone my age.

SHC

I swear "The ride is really amusing, it's kind of bouncy" is the reason we have to see a video haha

Steve, what do you think of this? Instead of two separate foils one continuous foil. Retractable above the bottom of the boat. Your version is simply brilliant particularly for a light air venue where you should foil earlier than any "normal" foil.

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DL, please don't drag this unrelated foil topic on in this thread. please.ironically it was baltic bandit that was pushing the hydro foil that went from hull to hull almost 2 years ago. He claimed it's a proven design. i don't know how that thing would slip up and down with out jamming up, or how it could flex enough to have one side down further than the other.

Having put that tangential information in the C Cat thread, i ask forgiveness.

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Steve, what do you think of this? Instead of two separate foils one continuous foil. Retractable above the bottom of the boat. Your version is simply brilliant particularly for a light air venue where you should foil earlier than any "normal" foil.

This might be lighter:

Dear Patent Office,

I would like to patent a new term, that being 'sNaKEfOIL'. Capitalization is CRITICAL!

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Doug, that is fucking StuPid; the horizontal area wetted surface would kill you, also it's very well for you to dream up this silly shit lying in the bath but that setup would twist lock solid, like jamb totally .... then WTF do you do. Please leave this to the C Class experts ... and you to go away

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Steve, what do you think of this? Instead of two separate foils one continuous foil. Retractable above the bottom of the boat. Your version is simply brilliant particularly for a light air venue where you should foil earlier than any "normal" foil.

This might be lighter:

Doug, your enthusiasm is great. Keep on pluggin'. But no. The intent of the SNAKEfOIL is actually not to get foiling sooner. There is no judge awarding points for simply being out of the water more. The boat has exited the water in light winds sooner than would be expected, but that was mainly a function of maxing out the foil trim and was on final analysis simply wasted energy picking up the boat. It definitely brought it below a fast catamaran's displacement-mode speed for that wind. In fact, I believe my dad's intent is the reverse of your assumption. The SNAKEfOIL (named for the board head's resemblance to that of a cobra, the caps bit is a self deprecating joke i.e. "snake oil") is a seven foot long slightly recurved straight board with a tightly curved head that acts as a cant control. This means that the board can be reverted to a cant angle of zero and simply zip along in displacement mode on the leeward side and be fully retracted from play on the windward side. This solves too problems in wind speeds where foiling is pointless. First, it eliminates the excess drag found in the horizontal component of a stereotypical catamaran hydrofoil when in displacement mode. This excess drag was poison to hydros in light air and Mischa went to arguably radical lengths to combat it. Second, the unretractable component of the stereotypical catamaran hydrofoil is a pain on the windward side in light air. It juts out sideways and drags just as you are starting to build speed and fly a hull. Ideally, the SNAKEfOIL should make it possible to glide along in sea-hugger mode in light air and foil in good breeze. That said, if the breeze is light, my money is on Cogito. She's the best boat for a drifter in the event, Benoit Marie knows what he's doing with the stick and Benoit Morelle is a seasoned veteran of strange lake geneva breeze. Let's bit forget that this is a boat race. I hope I've brought some clarity to all this.

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As you can see it acts just like an deep asymmetrical dagger board until we engage the head. Then it becomes a canted surface piercing foil.

A subtly is that the radius under the hull gets it deeper than if it was simply inclined in a straight trunk.

The head of the board is also symmetrical, which makes it quite fat for structure, but also reduces lift right at the surface, so it is less likely to gulp air. It also makes the boat more docile as the waterline travels up and down the curved span.

The reflex curve is so that the foil loses vertical projected area faster than it loses sideways projected area as the boat rises out of the water. We only intend to fly 12" or so in the air. Lots less windage down there. And the bow and stern are a whole lot more useful when things go wrong.

Paul Bogataj deserves all the credit for taking my various musings, observations, prejudices and observations and turning them into a coherent design. It is said a million times that design is all about compromise, inn this case I was willing to surrender righting moment for less drag and to not have extra wetted surface in light air and the giant sucking sound when the windward hydrofoil breaches the surface during the most critical part of the speed build.

Now that I understand Steves foil better-particularly the length-I realize that my "continuous" idea is way wrong. I overestimated the length of Steves foil based on the render below-and didn't do any calculations. It appeared to me to be almost as long as the distance between the hulls. That was an optical delusion on my part.

The idea of a single surface piercing foil that Steve is using is simply brilliant and offers a lot of potential-I hope he kicks ass with these foils!

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Steve - I know that you would be unwise and most likely unwilling to reveal technical data and construction solutions before the event (even if there is not enough time for competitors to copy your concepts) but can I request a thorough account after the event please?

Also - from what I can understand you need serious mechanical advantage to move the foil up or down (particularly at the curved section) but it struck me that you need serious purchase to get it down but that once deployed to a near horizontal layout in lift mode that it would continue to pull it self down and out through the hull - is that correct? - and so could you share how you firstly pull down and then solidly lock off any further unwanted deployment.

Further - if your foil is symmetrical at the curve but becoming asymmetrical (on the lower straighter recurved section) - how have you designed the case bearings to handle the differing shape and yet still be hydro dynamically smooth on the underside of the hull?

Can you share how you are controlling rudder elevator pitch on the fly? Is it Moth/I14 style tiller twist or cam activated via muscle boxes on the sterns? Again would love to know the details

How much cant angle can you achieve with the rig? - and is the aim to achieve verticality only; or do you over cant in breeze on (as the Orma 60's used to...) to achieve rig lift on the whole structure? With the rig cant deployed is there a residual tension in the tramp to allow it to remain in contact with the sole of the rig as it is eased off centreline for the endplate effect - or is the gap that would otherwise appear, just accepted as a consequence?

Hope you are as slippery as your namesake foil - a naming style that pokes fun in more than several ways! I have stated before that foils will evolve into shapes not even dreamt of yet and your solution is another example of that being proved.

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As you can see it acts just like an deep asymmetrical dagger board until we engage the head. Then it becomes a canted surface piercing foil.

A subtly is that the radius under the hull gets it deeper than if it was simply inclined in a straight trunk.

The head of the board is also symmetrical, which makes it quite fat for structure, but also reduces lift right at the surface, so it is less likely to gulp air. It also makes the boat more docile as the waterline travels up and down the curved span.

The reflex curve is so that the foil loses vertical projected area faster than it loses sideways projected area as the boat rises out of the water. We only intend to fly 12" or so in the air. Lots less windage down there. And the bow and stern are a whole lot more useful when things go wrong.

Paul Bogataj deserves all the credit for taking my various musings, observations, prejudices and observations and turning them into a coherent design. It is said a million times that design is all about compromise, inn this case I was willing to surrender righting moment for less drag and to not have extra wetted surface in light air and the giant sucking sound when the windward hydrofoil breaches the surface during the most critical part of the speed build.

Erich Chase built the boards, and did his usual great work.

It should be fun to see what happens if we get any wind at all.

SHC

I've alwalys wandered why foiling was done so high, if it was poossible to do it a bit over the surface, perhaps your system works well, good luck

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I don't believe anyone is losing any sleep over what I have come up with.

So there is no risk in spilling the beans.

Getting the board down isn't much of a problem as they are mostly pretty straight. getting it started around the corner takes a little doing, butt as the force vector offthe board turns upward, the load on the head starts to be downward. So the challenge ius to limit how far the board cants. Our early attempts were knocked over very easily, and ther board laughed at us. We drilled some holes and put some pins in, and they too got pretty quickly abused. Currently we have a 12mm titanium pin that prevents the head from disapearing from view. `

Hopefully the 33:1 acme treaded adusters will be up to the challenge. They provide just over1300 pounds tension in a fairly compact package. We can up the ante a bit more, but at that point I think we start ripping things off the boat.

The gap in the lower bearing is handled by a plastic gasket. Not perfect, but the lower bearing is a bit of a blister on the keelline, and the gap is on the high pressure side of the board so it doesn't seem to be all that bad. We don't hear lots of gurgling.

The rudder foil AoA is controlled by having the 2 down haul controls lead to a single lever on ther centerline of the stern beam. this in turn is cleated on both sides of the boat. I can adjust it from the wire, but I have to change hands and reach in to do so. It's pretty foolproof, I would like to have a twisty grip, but making that work with two rudders and with the tiller links is just a cluster.

We broke the beams that had the rig canting system on them. So that is being left on the table for further development. The class rules limit the extentr that you can cant the wing to the overall beam, so maximum canty angle for a more or lees full height wing is a bit less than 10 degrees. The consequences of canting the wing are more complicated than I thought at first. You get the CG of the wing to windward, but because the force vector has been rotated upward, you don't gain as much stability as you would expect. The wing canted to windward has less projected area, and therfore is less powered up, than the vertical wing. When we are foiling, we generally don't heel very much, so we may not need it after all. We did test one day against Cogito. With the wing canted, they kicked our ass hard enough that we almost gave up right there. I rerigged it and got it to work better, but we broke the beams, so it was pretty easy to give it up right after we changed our underwear.

SHC

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I don't believe anyone is losing any sleep over what I have come up with.

So there is no risk in spilling the beans.

Getting the board down isn't much of a problem as they are mostly pretty straight. getting it started around the corner takes a little doing, butt as the force vector offthe board turns upward, the load on the head starts to be downward. So the challenge ius to limit how far the board cants. Our early attempts were knocked over very easily, and ther board laughed at us. We drilled some holes and put some pins in, and they too got pretty quickly abused. Currently we have a 12mm titanium pin that prevents the head from disapearing from view. `

Hopefully the 33:1 acme treaded adusters will be up to the challenge. They provide just over1300 pounds tension in a fairly compact package. We can up the ante a bit more, but at that point I think we start ripping things off the boat.

The gap in the lower bearing is handled by a plastic gasket. Not perfect, but the lower bearing is a bit of a blister on the keelline, and the gap is on the high pressure side of the board so it doesn't seem to be all that bad. We don't hear lots of gurgling.

The rudder foil AoA is controlled by having the 2 down haul controls lead to a single lever on ther centerline of the stern beam. this in turn is cleated on both sides of the boat. I can adjust it from the wire, but I have to change hands and reach in to do so. It's pretty foolproof, I would like to have a twisty grip, but making that work with two rudders and with the tiller links is just a cluster.

We broke the beams that had the rig canting system on them. So that is being left on the table for further development. The class rules limit the extentr that you can cant the wing to the overall beam, so maximum canty angle for a more or lees full height wing is a bit less than 10 degrees. The consequences of canting the wing are more complicated than I thought at first. You get the CG of the wing to windward, but because the force vector has been rotated upward, you don't gain as much stability as you would expect. The wing canted to windward has less projected area, and therfore is less powered up, than the vertical wing. When we are foiling, we generally don't heel very much, so we may not need it after all. We did test one day against Cogito. With the wing canted, they kicked our ass hard enough that we almost gave up right there. I rerigged it and got it to work better, but we broke the beams, so it was pretty easy to give it up right after we changed our underwear.

SHC

Steve,

It seems like you are not doing things efficiently, if you wear brown underwear then there is no need to change. Sigh

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The wing canted to windward has less projected area, and therfore is less powered up, than the vertical wing.

Is projected area a real thing do you think Steve? At least in the way people used to talk about it? Ultimately the energy generated by the rig must be related to the number of air molecules that have their momentum changed per second, and the rig is going through the same number of air molecules no matter what angle its at. What must be different is the actual change in momentum, and if some of that is vertical rather than horizontal... I suppose its the same thing in the end, but projected area makes me think about ancient leadmines with stalled out sails on a dead run.

Its logical enough that the more lift you generate from a standard size rig then the less forward energy you generate, or is it more complicated than that? Suspect it may be. I suppose that because the foil areas are unlimited, and the rig area is limited it makes sense to have every bit of the sail area devoted to going forwards, and have all the lift generated by underwater foils even if you don't consider relative efficiencies.

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Nice idea Ben G - until you try to ease the main - and find that is pinned shut by the leeward shroud.....

Thanks for the response Steve - any danger of photos, showing us........everything!!!!!!

I can relate to the sensation of lack of stability as the rig is canted - this would be the reduction of displacement leading to a more frisky boat, No?

Stability is not the aim here anyway; more a drag reduction & realignment of the vectors in a more positive manner.

Removing the downward pressure of a rig canted to leeward (that increases displacement) to that that which reduces displacement generation of lift that is actually angled upward.

Can you shed any more insight into the stop pin arrangement? I would imagine that at the point of the curved section, that very small movements will re-direct the lift force over greatly different directions with big changes in lift versus leeway resistance and so ultimately in the feel and power of the boat. How active can you be with this function when fully wicked up?